docs: def new(self, operation='no operation', **kw):
          """
          Return a copy of the monitor usable for a different operation.
          """
          self_vars = vars(self).copy()
          del self_vars['operation']
          del self_vars['children']
          del self_vars['counts']
          del self_vars['_flush']
          new = self.__class__(operation)
          vars(new).update(self_vars)
          vars(new).update(kw)
          return new